According to the prior art, the image forming device includes an image carrier, a developing device, and a developer supply container for accommodating the developer. The developer supply container is provided with a developer discharging port for supplying the developer to the developing device.
When the developer is discharged from the developer supply container, a certain amount of air is required to enter the developer supply container to enhance the fluidity of the developer and the stability of the flow rate. Currently known developer supply containers on the market generally use a supply system where a bellows pump is used to assist the discharge of the developer. For example, Chinese Patent Publication No. CN103250102B discloses a developer supply container and a developer supply system where an appropriate amount of developer is discharged from the developer supply container to the developer replenishing device from the initial stage. The developer supply container mountable/detachable on the developer replenishing device includes: a container body for accommodating the developer; a discharging port for discharging the developer stored in the container body; a holding member to which a driving force is input from the developer replenishing device; a pumping part which is operated according to the driving force received by the holding member to repeatedly and alternately switch the internal pressure of the container body between a state with a pressure lower than the ambient pressure and a state with a pressure higher than the ambient pressure; and a managing part composed of the holding member and a locking member for managing the position of the pump part at the start of the operation, so that air is drawn into the container body from the discharging port during the period of the first operation cycle of the pump part. The developer supply container provided by the above patent can achieve a pressure inside the developer supply container lower than ambient pressure by the driving of the pump, so that the air flows into the developer replenishing container, thus enhancing the fluidity of the developer. The pressure inside the developer supply container also may be higher than the ambient pressure with the driving of the pump, so that the developer can be discharged and intermittently supplied to the developer.
However, the developer supply container of the above structure often causes the situation where the developer is over compacted by slight impact between the developer and the developer supply container due to the vibration during the transportation or storage. When the developer is in a compacted state, a large amount of developer may be completely discharged at one time when the developer is discharged, which is generally known as a gushing phenomenon. In addition, the developer supply container of the above structure often uses a single developer discharging port for alternate air inhale and exhale during operation. Such an air inhale and exhale method will slow down the discharge speed of the developer in a certain extent, and transport the developer at the nearby region of the developer discharging port into the developer supply container while inhaling air from the developer discharging port, thereby causing the lack of force for discharging the developer.